One assignee leads with 2,066 records in this dataset, well ahead of the rest of the ranked field — fifth place holds 142 and tenth place holds 89. The top five filers combined account for 59.9% of all 6,860 records in scope, and the top ten account for 68.2%. That concentration means a small number of equipment and materials suppliers control most of the claim space around clamping electrodes and chucking voltage control, so any competitive analysis should start with those leaders specifically rather than the field average.

Filings peaked at 379 in 2020 and the last fully comparable window shows a 26% decline, from 341 filings in 2021 to 254 in 2024. Because publication lags filing by roughly 18 months, 2025 and 2026 figures in any dataset are still filling in and should not be read as confirmation of further decline. The honest read is that the field has stepped down from its 2020 high, not that it is currently collapsing.

The IPC composition shows claims concentrated in H01L semiconductor devices (63.5% of the 6,860 records) and H10P (44.3%), but also spreading into C23C coating and surface deposition (27.1%), H01J electron and discharge tubes (26.2%), H02N electric machines (9.2%), H05B electric heating circuits (6.5%), G03F photolithography (5.4%) and C04B ceramics and refractories (4.7%). Because records can carry multiple IPC codes, these figures overlap rather than sum to 100%, reflecting how a single chuck patent often touches both the device layer and the coating or thermal system around it.